The ignition distributor generally comprises a rotor having an arm projecting from the center of rotation to the circumference of the distributor cap. At the center of rotation, the rotor arm is in electrical contact with a center electrode secured to the center of the cap and at the outer end the rotor arm is spaced from each one of outer electrodes mounted on the inner circumference of the cap. As the rotor turns a sudden breakdown of air occurs in the air gap between the rotor and stator outer electrodes generating a short-duration electric discharge or spark which lasts for a period of the order of nanoseconds, and which is a source of radio interference. An approach to the suppression of such radio interference involves the use of a coiled resistance element as the rotor arm which attenuates the flow of current generated as the result of the electric discharge. Another disadvantage encountered with the prior art approach is that the coiled structure is liable to electrical disconnection due to vehicle vibration, and hinders mass production because of its structural complexity.